1 /*
2 * Copyright (c) 2018, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotCacheAccess.hpp"
27 #include "cds/aotClassInitializer.hpp"
28 #include "cds/aotClassLocation.hpp"
29 #include "cds/aotCompressedPointers.hpp"
30 #include "cds/aotConstantPoolResolver.hpp"
31 #include "cds/aotLogging.hpp"
32 #include "cds/aotMappedHeapLoader.hpp"
33 #include "cds/aotMappedHeapWriter.hpp"
34 #include "cds/aotMetaspace.hpp"
35 #include "cds/aotOopChecker.hpp"
36 #include "cds/aotReferenceObjSupport.hpp"
37 #include "cds/aotStreamedHeapLoader.hpp"
38 #include "cds/aotStreamedHeapWriter.hpp"
39 #include "cds/archiveBuilder.hpp"
40 #include "cds/archiveUtils.hpp"
41 #include "cds/cds_globals.hpp"
42 #include "cds/cdsConfig.hpp"
43 #include "cds/cdsEnumKlass.hpp"
44 #include "cds/cdsHeapVerifier.hpp"
45 #include "cds/heapShared.inline.hpp"
46 #include "cds/regeneratedClasses.hpp"
47 #include "classfile/classLoaderData.hpp"
48 #include "classfile/javaClasses.inline.hpp"
49 #include "classfile/modules.hpp"
50 #include "classfile/stringTable.hpp"
51 #include "classfile/symbolTable.hpp"
52 #include "classfile/systemDictionary.hpp"
53 #include "classfile/systemDictionaryShared.hpp"
54 #include "classfile/vmClasses.hpp"
55 #include "classfile/vmSymbols.hpp"
56 #include "code/aotCodeCache.hpp"
57 #include "gc/shared/collectedHeap.hpp"
58 #include "gc/shared/gcLocker.hpp"
59 #include "gc/shared/gcVMOperations.hpp"
60 #include "logging/log.hpp"
61 #include "logging/logStream.hpp"
62 #include "memory/iterator.inline.hpp"
63 #include "memory/resourceArea.hpp"
64 #include "memory/universe.hpp"
65 #include "oops/compressedOops.inline.hpp"
66 #include "oops/fieldStreams.inline.hpp"
67 #include "oops/objArrayOop.inline.hpp"
68 #include "oops/oop.inline.hpp"
69 #include "oops/oopHandle.inline.hpp"
70 #include "oops/typeArrayOop.inline.hpp"
71 #include "prims/jvmtiExport.hpp"
72 #include "runtime/arguments.hpp"
73 #include "runtime/fieldDescriptor.inline.hpp"
74 #include "runtime/globals_extension.hpp"
75 #include "runtime/init.hpp"
76 #include "runtime/javaCalls.hpp"
77 #include "runtime/mutexLocker.hpp"
78 #include "runtime/safepointVerifiers.hpp"
79 #include "utilities/bitMap.inline.hpp"
80 #include "utilities/copy.hpp"
81 #if INCLUDE_G1GC
82 #include "gc/g1/g1CollectedHeap.hpp"
83 #endif
84
85 #if INCLUDE_CDS_JAVA_HEAP
86
87 struct ArchivableStaticFieldInfo {
88 const char* klass_name;
89 const char* field_name;
90 InstanceKlass* klass;
91 int offset;
92 BasicType type;
93
94 ArchivableStaticFieldInfo(const char* k, const char* f)
95 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
96
97 bool valid() {
98 return klass_name != nullptr;
99 }
100 };
101
102 HeapArchiveMode HeapShared::_heap_load_mode = HeapArchiveMode::_uninitialized;
103 HeapArchiveMode HeapShared::_heap_write_mode = HeapArchiveMode::_uninitialized;
104
105 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
106 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
107 size_t HeapShared::_total_obj_count;
108 size_t HeapShared::_total_obj_size;
109
110 #ifndef PRODUCT
111 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
112 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
113 static const char* _test_class_name = nullptr;
114 static Klass* _test_class = nullptr;
115 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
116 #endif
117
118
119 //
120 // If you add new entries to the following tables, you should know what you're doing!
121 //
122
123 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
124 {"java/lang/Integer$IntegerCache", "archivedCache"},
125 {"java/lang/Long$LongCache", "archivedCache"},
126 {"java/lang/Byte$ByteCache", "archivedCache"},
127 {"java/lang/Short$ShortCache", "archivedCache"},
128 {"java/lang/Character$CharacterCache", "archivedCache"},
129 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
130 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
131 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
132 {"java/util/ImmutableCollections", "archivedObjects"},
133 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
134 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
135 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
136 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
137
138 #ifndef PRODUCT
139 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
140 #endif
141 {nullptr, nullptr},
142 };
143
144 // full module graph
145 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
146 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
147 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
148 {"java/lang/Module$ArchivedData", "archivedData"},
149 {nullptr, nullptr},
150 };
151
152 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
153 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
154 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr;
155 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
156 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
157
158 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
159 for (int i = 0; fields[i].valid(); i++) {
160 if (fields[i].klass == ik) {
161 return true;
162 }
163 }
164 return false;
165 }
166
167 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
168 assert(CDSConfig::is_dumping_heap(), "dump-time only");
169 if (CDSConfig::is_dumping_klass_subgraphs()) {
170 // Legacy CDS archive support (to be deprecated)
171 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
172 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
173 } else {
174 return false;
175 }
176 }
177
178 oop HeapShared::CachedOopInfo::orig_referrer() const {
179 return _orig_referrer.resolve();
180 }
181
182 unsigned HeapShared::oop_hash(oop const& p) {
183 assert(SafepointSynchronize::is_at_safepoint() ||
184 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
185 // Do not call p->identity_hash() as that will update the
186 // object header.
187 return primitive_hash(cast_from_oop<intptr_t>(p));
188 }
189
190 // About the hashcode in the cached objects:
191 // - If a source object has a hashcode, it must be copied into the cache.
192 // That's because some cached hashtables are laid out using this hashcode.
193 // - If a source object doesn't have a hashcode, we avoid computing it while
194 // copying the objects into the cache. This will allow the hashcode to be
195 // dynamically and randomly computed in each production, which generally
196 // desirable to make the hashcodes more random between runs.
197 unsigned HeapShared::archived_object_cache_hash(OopHandle const& oh) {
198 oop o = oh.resolve();
199 if (_use_identity_hash_for_archived_object_cache) {
200 // This is called after all objects are copied. It's OK to update
201 // the object's hashcode.
202 //
203 // This may be called after we have left the AOT dumping safepoint.
204 // Objects in archived_object_cache() may be moved by the GC, so we
205 // can't use the address of o for computing the hash.
206 if (o == nullptr) {
207 return 0;
208 } else {
209 return o->identity_hash();
210 }
211 } else {
212 // This is called while we are copying the objects. Don't call o->identity_hash()
213 // as that will update the object header.
214 return oop_hash(o);
215 }
216 }
217
218 bool HeapShared::oop_handle_equals(const OopHandle& a, const OopHandle& b) {
219 return a.resolve() == b.resolve();
220 }
221
222 static void reset_states(oop obj, TRAPS) {
223 Handle h_obj(THREAD, obj);
224 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
225 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
226 Symbol* method_sig = vmSymbols::void_method_signature();
227
228 while (klass != nullptr) {
229 Method* method = klass->find_method(method_name, method_sig);
230 if (method != nullptr) {
231 assert(method->is_private(), "must be");
232 if (log_is_enabled(Debug, aot)) {
233 ResourceMark rm(THREAD);
234 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
235 }
236 JavaValue result(T_VOID);
237 JavaCalls::call_special(&result, h_obj, klass,
238 method_name, method_sig, CHECK);
239 }
240 klass = klass->super();
241 }
242 }
243
244 void HeapShared::reset_archived_object_states(TRAPS) {
245 assert(CDSConfig::is_dumping_heap(), "dump-time only");
246 log_debug(aot)("Resetting platform loader");
247 reset_states(SystemDictionary::java_platform_loader(), CHECK);
248 log_debug(aot)("Resetting system loader");
249 reset_states(SystemDictionary::java_system_loader(), CHECK);
250
251 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
252 // directly used for class loading, but rather is used by the core library
253 // to keep track of resources, etc, loaded by the null class loader.
254 //
255 // Note, this object is non-null, and is not the same as
256 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
257 // which is null.
258 log_debug(aot)("Resetting boot loader");
259 JavaValue result(T_OBJECT);
260 JavaCalls::call_static(&result,
261 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
262 vmSymbols::bootLoader_name(),
263 vmSymbols::void_BuiltinClassLoader_signature(),
264 CHECK);
265 Handle boot_loader(THREAD, result.get_oop());
266 reset_states(boot_loader(), CHECK);
267 }
268
269 void HeapShared::ensure_determinism(TRAPS) {
270 TempNewSymbol class_name = SymbolTable::new_symbol("jdk/internal/util/WeakReferenceKey");
271 TempNewSymbol method_name = SymbolTable::new_symbol("ensureDeterministicAOTCache");
272
273 Klass* weak_ref_key_class = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
274 precond(weak_ref_key_class != nullptr);
275
276 log_debug(aot)("Calling WeakReferenceKey::ensureDeterministicAOTCache(Object.class)");
277 JavaValue result(T_BOOLEAN);
278 JavaCalls::call_static(&result,
279 weak_ref_key_class,
280 method_name,
281 vmSymbols::void_boolean_signature(),
282 CHECK);
283 assert(result.get_jboolean() == false, "sanity");
284 }
285
286 void HeapShared::prepare_for_archiving(TRAPS) {
287 reset_archived_object_states(CHECK);
288 ensure_determinism(CHECK);
289 }
290
291 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
292 bool HeapShared::_use_identity_hash_for_archived_object_cache = false;
293
294 bool HeapShared::is_archived_heap_in_use() {
295 if (HeapShared::is_loading()) {
296 if (HeapShared::is_loading_streaming_mode()) {
297 return AOTStreamedHeapLoader::is_in_use();
298 } else {
299 return AOTMappedHeapLoader::is_in_use();
300 }
301 }
302
303 return false;
304 }
305
306 bool HeapShared::can_use_archived_heap() {
307 FileMapInfo* static_mapinfo = FileMapInfo::current_info();
308 if (static_mapinfo == nullptr) {
309 return false;
310 }
311 if (!static_mapinfo->has_heap_region()) {
312 return false;
313 }
314 if (!static_mapinfo->object_streaming_mode() &&
315 !Universe::heap()->can_load_archived_objects() &&
316 !UseG1GC) {
317 // Incompatible object format
318 return false;
319 }
320
321 return true;
322 }
323
324 bool HeapShared::is_too_large_to_archive(size_t size) {
325 if (HeapShared::is_writing_streaming_mode()) {
326 return false;
327 } else {
328 return AOTMappedHeapWriter::is_too_large_to_archive(size);
329 }
330 }
331
332 bool HeapShared::is_too_large_to_archive(oop obj) {
333 if (HeapShared::is_writing_streaming_mode()) {
334 return false;
335 } else {
336 return AOTMappedHeapWriter::is_too_large_to_archive(obj);
337 }
338 }
339
340 bool HeapShared::is_string_too_large_to_archive(oop string) {
341 typeArrayOop value = java_lang_String::value_no_keepalive(string);
342 return is_too_large_to_archive(value);
343 }
344
345 void HeapShared::initialize_loading_mode(HeapArchiveMode mode) {
346 assert(_heap_load_mode == HeapArchiveMode::_uninitialized, "already set?");
347 assert(mode != HeapArchiveMode::_uninitialized, "sanity");
348 _heap_load_mode = mode;
349 };
350
351 void HeapShared::initialize_writing_mode() {
352 assert(!FLAG_IS_ERGO(AOTStreamableObjects), "Should not have been ergonomically set yet");
353
354 if (!CDSConfig::is_dumping_archive()) {
355 // We use FLAG_IS_CMDLINE below because we are specifically looking to warn
356 // a user that explicitly sets the flag on the command line for a JVM that is
357 // not dumping an archive.
358 if (FLAG_IS_CMDLINE(AOTStreamableObjects)) {
359 log_warning(cds)("-XX:%cAOTStreamableObjects was specified, "
360 "AOTStreamableObjects is only used for writing "
361 "the AOT cache.",
362 AOTStreamableObjects ? '+' : '-');
363 }
364 }
365
366 // The below checks use !FLAG_IS_DEFAULT instead of FLAG_IS_CMDLINE
367 // because the one step AOT cache creation transfers the AOTStreamableObjects
368 // flag value from the training JVM to the assembly JVM using an environment
369 // variable that sets the flag as ERGO in the assembly JVM.
370 if (FLAG_IS_DEFAULT(AOTStreamableObjects)) {
371 // By default, the value of AOTStreamableObjects should match !UseCompressedOops.
372 FLAG_SET_DEFAULT(AOTStreamableObjects, !UseCompressedOops);
373 } else if (!AOTStreamableObjects && UseZGC) {
374 // Never write mapped heap with ZGC
375 if (CDSConfig::is_dumping_archive()) {
376 log_warning(cds)("Heap archiving without streaming not supported for -XX:+UseZGC");
377 }
378 FLAG_SET_ERGO(AOTStreamableObjects, true);
379 }
380
381 if (CDSConfig::is_dumping_archive()) {
382 // Select default mode
383 assert(_heap_write_mode == HeapArchiveMode::_uninitialized, "already initialized?");
384 _heap_write_mode = AOTStreamableObjects ? HeapArchiveMode::_streaming : HeapArchiveMode::_mapping;
385 }
386 }
387
388 void HeapShared::initialize_streaming() {
389 assert(is_loading_streaming_mode(), "shouldn't call this");
390 if (can_use_archived_heap()) {
391 AOTStreamedHeapLoader::initialize();
392 }
393 }
394
395 void HeapShared::enable_gc() {
396 if (AOTStreamedHeapLoader::is_in_use()) {
397 AOTStreamedHeapLoader::enable_gc();
398 }
399 }
400
401 void HeapShared::materialize_thread_object() {
402 if (AOTStreamedHeapLoader::is_in_use()) {
403 AOTStreamedHeapLoader::materialize_thread_object();
404 }
405 }
406
407 void HeapShared::archive_interned_string(oop string) {
408 assert(HeapShared::is_writing_mapping_mode(), "Only used by this mode");
409 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, string);
410 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
411 }
412
413 void HeapShared::finalize_initialization(FileMapInfo* static_mapinfo) {
414 if (HeapShared::is_loading()) {
415 if (HeapShared::is_loading_streaming_mode()) {
416 // Heap initialization can be done only after vtables are initialized by ReadClosure.
417 AOTStreamedHeapLoader::finish_initialization(static_mapinfo);
418 } else {
419 // Finish up archived heap initialization. These must be
420 // done after ReadClosure.
421 AOTMappedHeapLoader::finish_initialization(static_mapinfo);
422 }
423 }
424 }
425
426 void HeapShared::make_archived_object_cache_gc_safe() {
427 ArchivedObjectCache* new_cache = new (mtClass)ArchivedObjectCache(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
428
429 // It's safe to change the behavior of the hash function now, because iterate_all()
430 // doesn't call the hash function.
431 _use_identity_hash_for_archived_object_cache = true;
432
433 // Copy all CachedOopInfo into a new table using a different hashing algorithm
434 archived_object_cache()->iterate_all([&] (OopHandle oh, CachedOopInfo info) {
435 new_cache->put_when_absent(oh, info);
436 });
437
438 destroy_archived_object_cache();
439 _archived_object_cache = new_cache;
440 }
441
442 HeapShared::CachedOopInfo* HeapShared::get_cached_oop_info(oop obj) {
443 OopHandle oh(Universe::vm_global(), obj);
444 CachedOopInfo* result = _archived_object_cache->get(oh);
445 oh.release(Universe::vm_global());
446 return result;
447 }
448
449 bool HeapShared::has_been_archived(oop obj) {
450 assert(CDSConfig::is_dumping_heap(), "dump-time only");
451 return get_cached_oop_info(obj) != nullptr;
452 }
453
454 int HeapShared::append_root(oop obj) {
455 assert(SafepointSynchronize::is_at_safepoint(), "sanity");
456 assert(CDSConfig::is_dumping_heap(), "dump-time only");
457 assert(_pending_roots != nullptr, "sanity");
458
459 if (obj == nullptr) {
460 assert(_pending_roots->at(0) == nullptr, "root index 1 is always null");
461 return 0;
462 } else if (CDSConfig::is_dumping_aot_linked_classes()) {
463 // The AOT compiler may refer the same obj many times, so we
464 // should use the same index for this oop to avoid excessive entries
465 // in the roots array.
466 CachedOopInfo* obj_info = get_cached_oop_info(obj);
467 assert(obj_info != nullptr, "must be archived");
468
469 if (obj_info->root_index() > 0) {
470 return obj_info->root_index();
471 } else {
472 int i = _pending_roots->append(obj);
473 obj_info->set_root_index(i);
474 return i;
475 }
476 } else {
477 return _pending_roots->append(obj);
478 }
479 }
480
481 int HeapShared::get_root_index(oop obj) {
482 if (java_lang_Class::is_instance(obj)) {
483 obj = scratch_java_mirror(obj);
484 }
485
486 CachedOopInfo* obj_info = get_cached_oop_info(obj);
487 const char* error = nullptr;
488 if (obj_info == nullptr) {
489 error = "Not a cached oop";
490 } else if (obj_info->root_index() < 0) {
491 error = "Not a cached oop root";
492 } else {
493 return obj_info->root_index();
494 }
495
496 ResourceMark rm;
497 log_debug(aot, codecache, oops)("%s: " INTPTR_FORMAT " (%s)", error,
498 cast_from_oop<uintptr_t>(obj),
499 obj->klass()->external_name());
500 return -1;
501 }
502
503 oop HeapShared::get_root(int index, bool clear) {
504 assert(index >= 0, "sanity");
505 assert(is_archived_heap_in_use(), "getting roots into heap that is not used");
506
507 oop result;
508 if (HeapShared::is_loading_streaming_mode()) {
509 result = AOTStreamedHeapLoader::get_root(index);
510 } else {
511 assert(HeapShared::is_loading_mapping_mode(), "must be");
512 result = AOTMappedHeapLoader::get_root(index);
513 }
514
515 if (clear) {
516 clear_root(index);
517 }
518
519 return result;
520 }
521
522 void HeapShared::finish_materialize_objects() {
523 if (AOTStreamedHeapLoader::is_in_use()) {
524 AOTStreamedHeapLoader::finish_materialize_objects();
525 }
526 }
527
528 void HeapShared::clear_root(int index) {
529 if (CDSConfig::is_using_aot_linked_classes()) {
530 // When AOT linked classes are in use, all roots will be in use all
531 // the time, there's no benefit for clearing the roots. Also, we
532 // can't clear the roots as they can be shared.
533 return;
534 }
535
536 assert(index >= 0, "sanity");
537 assert(CDSConfig::is_using_archive(), "must be");
538 if (is_archived_heap_in_use()) {
539 if (log_is_enabled(Debug, aot, heap)) {
540 log_debug(aot, heap)("Clearing root %d: was %zu", index, p2i(get_root(index, false /* clear */)));
541 }
542 if (HeapShared::is_loading_streaming_mode()) {
543 AOTStreamedHeapLoader::clear_root(index);
544 } else {
545 assert(HeapShared::is_loading_mapping_mode(), "must be");
546 AOTMappedHeapLoader::clear_root(index);
547 }
548 }
549 }
550
551 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
552 assert(CDSConfig::is_dumping_heap(), "dump-time only");
553
554 assert(!obj->is_stackChunk(), "do not archive stack chunks");
555 if (has_been_archived(obj)) {
556 return true;
557 }
558
559 if (is_too_large_to_archive(obj)) {
560 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
561 p2i(obj), obj->size());
562 debug_trace();
563 return false;
564 }
565
566 AOTOopChecker::check(obj); // Make sure contents of this oop are safe.
567 count_allocation(obj->size());
568
569 if (HeapShared::is_writing_streaming_mode()) {
570 AOTStreamedHeapWriter::add_source_obj(obj);
571 } else {
572 AOTMappedHeapWriter::add_source_obj(obj);
573 }
574
575 OopHandle oh(Universe::vm_global(), obj);
576 CachedOopInfo info = make_cached_oop_info(obj, referrer);
577 archived_object_cache()->put_when_absent(oh, info);
578 archived_object_cache()->maybe_grow();
579
580 Klass* k = obj->klass();
581 if (k->is_instance_klass()) {
582 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
583 // This ensures that during the production run, whenever Java code sees a cached object
584 // of type X, we know that X is already initialized. (see TODO comment below ...)
585
586 if (InstanceKlass::cast(k)->is_enum_subclass()
587 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
588 // we must store them as AOT-initialized.
589 || (subgraph_info == _dump_time_special_subgraph))
590 // TODO: we do this only for the special subgraph for now. Extending this to
591 // other subgraphs would require more refactoring of the core library (such as
592 // move some initialization logic into runtimeSetup()).
593 //
594 // For the other subgraphs, we have a weaker mechanism to ensure that
595 // all classes in a subgraph are initialized before the subgraph is programmatically
596 // returned from jdk.internal.misc.CDS::initializeFromArchive().
597 // See HeapShared::initialize_from_archived_subgraph().
598 {
599 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
600 }
601
602 if (java_lang_Class::is_instance(obj)) {
603 Klass* mirror_k = java_lang_Class::as_Klass(obj);
604 if (mirror_k != nullptr) {
605 AOTArtifactFinder::add_cached_class(mirror_k);
606 }
607 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
608 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
609 if (m != nullptr) {
610 if (RegeneratedClasses::has_been_regenerated(m)) {
611 m = RegeneratedClasses::get_regenerated_object(m);
612 }
613 InstanceKlass* method_holder = m->method_holder();
614 AOTArtifactFinder::add_cached_class(method_holder);
615 }
616 } else if (AOTCodeCache::is_dumping_code() &&
617 (java_lang_invoke_MethodHandle::is_instance(obj) || is_interned_string(obj))) {
618 // Needed by AOT compiler.
619 append_root(obj);
620 }
621 }
622
623 if (log_is_enabled(Debug, aot, heap)) {
624 ResourceMark rm;
625 LogTarget(Debug, aot, heap) log;
626 LogStream out(log);
627 out.print("Archived heap object " PTR_FORMAT " : %s ",
628 p2i(obj), obj->klass()->external_name());
629 if (java_lang_Class::is_instance(obj)) {
630 Klass* k = java_lang_Class::as_Klass(obj);
631 if (k != nullptr) {
632 out.print("%s", k->external_name());
633 } else {
634 out.print("primitive");
635 }
636 }
637 out.cr();
638 }
639
640 return true;
641 }
642
643 class MetaspaceObjToOopHandleTable: public HashTable<MetaspaceObj*, OopHandle,
644 36137, // prime number
645 AnyObj::C_HEAP,
646 mtClassShared> {
647 public:
648 oop get_oop(MetaspaceObj* ptr) {
649 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
650 OopHandle* handle = get(ptr);
651 if (handle != nullptr) {
652 return handle->resolve();
653 } else {
654 return nullptr;
655 }
656 }
657 void set_oop(MetaspaceObj* ptr, oop o) {
658 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
659 OopHandle handle(Universe::vm_global(), o);
660 put_when_absent(ptr, handle);
661 }
662 void remove_oop(MetaspaceObj* ptr) {
663 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
664 OopHandle* handle = get(ptr);
665 if (handle != nullptr) {
666 handle->release(Universe::vm_global());
667 remove(ptr);
668 }
669 }
670 };
671
672 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
673 if (CDSConfig::is_dumping_preimage_static_archive() && scratch_resolved_references(src) != nullptr) {
674 // We are in AOT training run. The class has been redefined and we are giving it a new resolved_reference.
675 // Ignore it, as this class will be excluded from the AOT config.
676 return;
677 }
678 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
679 _scratch_objects_table->set_oop(src, dest);
680 }
681 }
682
683 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
684 return (objArrayOop)_scratch_objects_table->get_oop(src);
685 }
686
687 void HeapShared::init_dumping() {
688 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
689 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
690 _pending_roots->append(nullptr); // root index 0 represents a null oop
691 }
692
693 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
694 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
695 BasicType bt = (BasicType)i;
696 if (!is_reference_type(bt)) {
697 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
698 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
699 }
700 }
701 }
702
703 // Given java_mirror that represents a (primitive or reference) type T,
704 // return the "scratch" version that represents the same type T. Note
705 // that java_mirror will be returned if the mirror is already a scratch mirror.
706 //
707 // See java_lang_Class::create_scratch_mirror() for more info.
708 oop HeapShared::scratch_java_mirror(oop java_mirror) {
709 assert(java_lang_Class::is_instance(java_mirror), "must be");
710
711 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
712 BasicType bt = (BasicType)i;
713 if (!is_reference_type(bt)) {
714 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
715 return java_mirror;
716 }
717 }
718 }
719
720 if (java_lang_Class::is_primitive(java_mirror)) {
721 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
722 } else {
723 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
724 }
725 }
726
727 oop HeapShared::scratch_java_mirror(BasicType t) {
728 assert((uint)t < T_VOID+1, "range check");
729 assert(!is_reference_type(t), "sanity");
730 return _scratch_basic_type_mirrors[t].resolve();
731 }
732
733 oop HeapShared::scratch_java_mirror(Klass* k) {
734 return _scratch_objects_table->get_oop(k);
735 }
736
737 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
738 _scratch_objects_table->set_oop(k, mirror);
739 }
740
741 void HeapShared::remove_scratch_objects(Klass* k) {
742 // Klass is being deallocated. Java mirror can still be alive, and it should not
743 // point to dead klass. We need to break the link from mirror to the Klass.
744 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
745 oop mirror = _scratch_objects_table->get_oop(k);
746 if (mirror != nullptr) {
747 java_lang_Class::set_klass(mirror, nullptr);
748 }
749 _scratch_objects_table->remove_oop(k);
750 if (k->is_instance_klass()) {
751 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
752 }
753 }
754
755 //TODO: we eventually want a more direct test for these kinds of things.
756 //For example the JVM could record some bit of context from the creation
757 //of the klass, such as who called the hidden class factory. Using
758 //string compares on names is fragile and will break as soon as somebody
759 //changes the names in the JDK code. See discussion in JDK-8342481 for
760 //related ideas about marking AOT-related classes.
761 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
762 return ik->is_hidden() &&
763 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
764 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
765 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
766 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
767 }
768
769 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
770 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
771 }
772
773 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
774 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
775 }
776
777 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
778 return CDSConfig::is_dumping_method_handles() &&
779 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
780 }
781
782
783 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
784 ik->set_has_aot_initialized_mirror();
785
786 oop orig_mirror;
787 if (RegeneratedClasses::is_regenerated_object(ik)) {
788 InstanceKlass* orig_ik = RegeneratedClasses::get_original_object(ik);
789 precond(orig_ik->is_initialized());
790 orig_mirror = orig_ik->java_mirror();
791 } else {
792 precond(ik->is_initialized());
793 orig_mirror = ik->java_mirror();
794 }
795
796 oop m = scratch_java_mirror(ik);
797 int nfields = 0;
798 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
799 if (fs.access_flags().is_static()) {
800 fieldDescriptor& fd = fs.field_descriptor();
801 int offset = fd.offset();
802 switch (fd.field_type()) {
803 case T_OBJECT:
804 case T_ARRAY:
805 {
806 oop field_obj = orig_mirror->obj_field(offset);
807 m->obj_field_put(offset, field_obj);
808 if (field_obj != nullptr) {
809 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
810 assert(success, "sanity");
811 }
812 }
813 break;
814 case T_BOOLEAN:
815 m->bool_field_put(offset, orig_mirror->bool_field(offset));
816 break;
817 case T_BYTE:
818 m->byte_field_put(offset, orig_mirror->byte_field(offset));
819 break;
820 case T_SHORT:
821 m->short_field_put(offset, orig_mirror->short_field(offset));
822 break;
823 case T_CHAR:
824 m->char_field_put(offset, orig_mirror->char_field(offset));
825 break;
826 case T_INT:
827 m->int_field_put(offset, orig_mirror->int_field(offset));
828 break;
829 case T_LONG:
830 m->long_field_put(offset, orig_mirror->long_field(offset));
831 break;
832 case T_FLOAT:
833 m->float_field_put(offset, orig_mirror->float_field(offset));
834 break;
835 case T_DOUBLE:
836 m->double_field_put(offset, orig_mirror->double_field(offset));
837 break;
838 default:
839 ShouldNotReachHere();
840 }
841 nfields ++;
842 }
843 }
844
845 oop class_data = java_lang_Class::class_data(orig_mirror);
846 java_lang_Class::set_class_data(m, class_data);
847 if (class_data != nullptr) {
848 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
849 assert(success, "sanity");
850 }
851
852 if (log_is_enabled(Debug, aot, init)) {
853 ResourceMark rm;
854 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
855 ik->is_hidden() ? " (hidden)" : "",
856 ik->is_enum_subclass() ? " (enum)" : "");
857 }
858 }
859
860 void HeapShared::copy_java_mirror(oop orig_mirror, oop scratch_m) {
861 // We need to retain the identity_hash, because it may have been used by some hashtables
862 // in the shared heap.
863 if (!orig_mirror->fast_no_hash_check()) {
864 intptr_t src_hash = orig_mirror->identity_hash();
865 if (UseCompactObjectHeaders) {
866 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
867 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
868 } else {
869 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
870 }
871 assert(scratch_m->mark().is_unlocked(), "sanity");
872
873 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
874 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
875 }
876
877 if (CDSConfig::is_dumping_aot_linked_classes()) {
878 java_lang_Class::set_module(scratch_m, java_lang_Class::module(orig_mirror));
879 java_lang_Class::set_protection_domain(scratch_m, java_lang_Class::protection_domain(orig_mirror));
880 }
881
882 Klass* k = java_lang_Class::as_Klass(orig_mirror); // is null Universe::void_mirror();
883 if (CDSConfig::is_dumping_reflection_data() &&
884 k != nullptr && k->is_instance_klass() &&
885 java_lang_Class::reflection_data(orig_mirror) != nullptr &&
886 AOTConstantPoolResolver::can_archive_reflection_data(InstanceKlass::cast(k))) {
887 java_lang_Class::set_reflection_data(scratch_m, java_lang_Class::reflection_data(orig_mirror));
888 }
889 }
890
891 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
892 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
893 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
894 if (rr != nullptr && !HeapShared::is_too_large_to_archive(rr)) {
895 return HeapShared::scratch_resolved_references(src_ik->constants());
896 }
897 }
898 return nullptr;
899 }
900
901 int HeapShared::archive_exception_instance(oop exception) {
902 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
903 assert(success, "sanity");
904 return append_root(exception);
905 }
906
907 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
908 OopHandle oh(&src_obj);
909 CachedOopInfo* info = archived_object_cache()->get(oh);
910 assert(info != nullptr, "must be");
911 has_oop_pointers = info->has_oop_pointers();
912 has_native_pointers = info->has_native_pointers();
913 }
914
915 void HeapShared::set_has_native_pointers(oop src_obj) {
916 OopHandle oh(&src_obj);
917 CachedOopInfo* info = archived_object_cache()->get(oh);
918 assert(info != nullptr, "must be");
919 info->set_has_native_pointers();
920 }
921
922 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
923 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
924 void HeapShared::start_scanning_for_oops() {
925 {
926 NoSafepointVerifier nsv;
927
928 // The special subgraph doesn't belong to any class. We use Object_klass() here just
929 // for convenience.
930 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
931
932 // Cache for recording where the archived objects are copied to
933 create_archived_object_cache();
934
935 if (HeapShared::is_writing_mapping_mode() && (UseG1GC || UseCompressedOops)) {
936 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
937 UseCompressedOops ? p2i(CompressedOops::begin()) :
938 p2i((address)G1CollectedHeap::heap()->reserved().start()),
939 UseCompressedOops ? p2i(CompressedOops::end()) :
940 p2i((address)G1CollectedHeap::heap()->reserved().end()));
941 }
942
943 archive_subgraphs();
944 }
945
946 init_seen_objects_table();
947 Universe::archive_exception_instances();
948 }
949
950 void HeapShared::end_scanning_for_oops() {
951 if (is_writing_mapping_mode()) {
952 StringTable::init_shared_table();
953 }
954 delete_seen_objects_table();
955 }
956
957 void HeapShared::write_heap(AOTMappedHeapInfo* mapped_heap_info, AOTStreamedHeapInfo* streamed_heap_info) {
958 {
959 NoSafepointVerifier nsv;
960 if (!SkipArchiveHeapVerification) {
961 CDSHeapVerifier::verify();
962 }
963 check_special_subgraph_classes();
964 }
965
966 if (HeapShared::is_writing_mapping_mode()) {
967 StringTable::write_shared_table();
968 AOTMappedHeapWriter::write(_pending_roots, mapped_heap_info);
969 } else {
970 assert(HeapShared::is_writing_streaming_mode(), "are there more modes?");
971 AOTStreamedHeapWriter::write(_pending_roots, streamed_heap_info);
972 }
973
974 ArchiveBuilder::OtherROAllocMark mark;
975 write_subgraph_info_table();
976
977 delete _pending_roots;
978 _pending_roots = nullptr;
979
980 make_archived_object_cache_gc_safe();
981 }
982
983 void HeapShared::scan_java_mirror(oop orig_mirror) {
984 oop m = scratch_java_mirror(orig_mirror);
985 if (m != nullptr) { // nullptr if for custom class loader
986 copy_java_mirror(orig_mirror, m);
987 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
988 assert(success, "sanity");
989
990 oop extra;
991 if ((extra = java_lang_Class::reflection_data(m)) != nullptr) {
992 success = archive_reachable_objects_from(1, _dump_time_special_subgraph, extra);
993 assert(success, "sanity");
994 }
995 }
996 }
997
998 void HeapShared::scan_java_class(Klass* orig_k) {
999 scan_java_mirror(orig_k->java_mirror());
1000
1001 if (orig_k->is_instance_klass()) {
1002 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
1003 orig_ik->constants()->prepare_resolved_references_for_archiving();
1004 objArrayOop rr = get_archived_resolved_references(orig_ik);
1005 if (rr != nullptr) {
1006 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
1007 assert(success, "must be");
1008 }
1009 }
1010 }
1011
1012 void HeapShared::archive_subgraphs() {
1013 assert(CDSConfig::is_dumping_heap(), "must be");
1014
1015 if (CDSConfig::is_dumping_klass_subgraphs()) {
1016 archive_object_subgraphs(archive_subgraph_entry_fields,
1017 false /* is_full_module_graph */);
1018 if (CDSConfig::is_dumping_full_module_graph()) {
1019 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
1020 true /* is_full_module_graph */);
1021 }
1022 }
1023 }
1024
1025 //
1026 // Subgraph archiving support
1027 //
1028 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
1029 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
1030
1031 // Get the subgraph_info for Klass k. A new subgraph_info is created if
1032 // there is no existing one for k. The subgraph_info records the "buffered"
1033 // address of the class.
1034 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
1035 assert(CDSConfig::is_dumping_heap(), "dump time only");
1036 bool created;
1037 KlassSubGraphInfo* info =
1038 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
1039 &created);
1040 assert(created, "must not initialize twice");
1041 return info;
1042 }
1043
1044 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
1045 assert(CDSConfig::is_dumping_heap(), "dump time only");
1046 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
1047 assert(info != nullptr, "must have been initialized");
1048 return info;
1049 }
1050
1051 // Add an entry field to the current KlassSubGraphInfo.
1052 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
1053 assert(CDSConfig::is_dumping_heap(), "dump time only");
1054 if (_subgraph_entry_fields == nullptr) {
1055 _subgraph_entry_fields =
1056 new (mtClass) GrowableArray<int>(10, mtClass);
1057 }
1058 _subgraph_entry_fields->append(static_field_offset);
1059 if (v == nullptr) {
1060 _subgraph_entry_fields->append(-1);
1061 } else {
1062 _subgraph_entry_fields->append(HeapShared::append_root(v));
1063 }
1064 }
1065
1066 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
1067 // Only objects of boot classes can be included in sub-graph.
1068 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
1069 assert(CDSConfig::is_dumping_heap(), "dump time only");
1070
1071 if (_subgraph_object_klasses == nullptr) {
1072 _subgraph_object_klasses =
1073 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1074 }
1075
1076 if (_k == orig_k) {
1077 // Don't add the Klass containing the sub-graph to it's own klass
1078 // initialization list.
1079 return;
1080 }
1081
1082 if (orig_k->is_instance_klass()) {
1083 #ifdef ASSERT
1084 InstanceKlass* ik = InstanceKlass::cast(orig_k);
1085 if (CDSConfig::is_dumping_method_handles()) {
1086 // -XX:AOTInitTestClass must be used carefully in regression tests to
1087 // include only classes that are safe to aot-initialize.
1088 assert(ik->class_loader() == nullptr ||
1089 HeapShared::is_lambda_proxy_klass(ik) ||
1090 AOTClassInitializer::has_test_class(),
1091 "we can archive only instances of boot classes or lambda proxy classes");
1092 } else {
1093 assert(ik->class_loader() == nullptr, "must be boot class");
1094 }
1095 #endif
1096 // vmClasses::xxx_klass() are not updated, need to check
1097 // the original Klass*
1098 if (orig_k == vmClasses::String_klass() ||
1099 orig_k == vmClasses::Object_klass()) {
1100 // Initialized early during VM initialization. No need to be added
1101 // to the sub-graph object class list.
1102 return;
1103 }
1104 check_allowed_klass(InstanceKlass::cast(orig_k));
1105 } else if (orig_k->is_objArray_klass()) {
1106 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1107 if (abk->is_instance_klass()) {
1108 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1109 "must be boot class");
1110 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1111 }
1112 if (orig_k == Universe::objectArrayKlass()) {
1113 // Initialized early during Universe::genesis. No need to be added
1114 // to the list.
1115 return;
1116 }
1117 } else {
1118 assert(orig_k->is_typeArray_klass(), "must be");
1119 // Primitive type arrays are created early during Universe::genesis.
1120 return;
1121 }
1122
1123 if (log_is_enabled(Debug, aot, heap)) {
1124 if (!_subgraph_object_klasses->contains(orig_k)) {
1125 ResourceMark rm;
1126 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1127 }
1128 }
1129
1130 _subgraph_object_klasses->append_if_missing(orig_k);
1131 _has_non_early_klasses |= is_non_early_klass(orig_k);
1132 }
1133
1134 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1135 #ifndef PRODUCT
1136 if (AOTClassInitializer::has_test_class()) {
1137 // The tests can cache arbitrary types of objects.
1138 return;
1139 }
1140 #endif
1141
1142 if (ik->module()->name() == vmSymbols::java_base()) {
1143 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1144 return;
1145 }
1146
1147 const char* lambda_msg = "";
1148 if (CDSConfig::is_dumping_method_handles()) {
1149 lambda_msg = ", or a lambda proxy class";
1150 if (HeapShared::is_lambda_proxy_klass(ik) &&
1151 (ik->class_loader() == nullptr ||
1152 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1153 ik->class_loader() == SystemDictionary::java_system_loader())) {
1154 return;
1155 }
1156 }
1157
1158 #ifndef PRODUCT
1159 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1160 // This class is loaded by ArchiveHeapTestClass
1161 return;
1162 }
1163 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1164 #else
1165 const char* testcls_msg = "";
1166 #endif
1167
1168 ResourceMark rm;
1169 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1170 ik->external_name(), lambda_msg, testcls_msg);
1171 AOTMetaspace::unrecoverable_writing_error();
1172 }
1173
1174 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1175 if (k->is_objArray_klass()) {
1176 k = ObjArrayKlass::cast(k)->bottom_klass();
1177 }
1178 if (k->is_instance_klass()) {
1179 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1180 ResourceMark rm;
1181 log_info(aot, heap)("non-early: %s", k->external_name());
1182 return true;
1183 } else {
1184 return false;
1185 }
1186 } else {
1187 return false;
1188 }
1189 }
1190
1191 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1192 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1193 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1194 _entry_field_records = nullptr;
1195 _subgraph_object_klasses = nullptr;
1196 _is_full_module_graph = info->is_full_module_graph();
1197
1198 if (_is_full_module_graph) {
1199 // Consider all classes referenced by the full module graph as early -- we will be
1200 // allocating objects of these classes during JVMTI early phase, so they cannot
1201 // be processed by (non-early) JVMTI ClassFileLoadHook
1202 _has_non_early_klasses = false;
1203 } else {
1204 _has_non_early_klasses = info->has_non_early_klasses();
1205 }
1206
1207 if (_has_non_early_klasses) {
1208 ResourceMark rm;
1209 log_info(aot, heap)(
1210 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1211 _k->external_name());
1212 }
1213
1214 // populate the entry fields
1215 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1216 if (entry_fields != nullptr) {
1217 int num_entry_fields = entry_fields->length();
1218 assert(num_entry_fields % 2 == 0, "sanity");
1219 _entry_field_records =
1220 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1221 for (int i = 0 ; i < num_entry_fields; i++) {
1222 _entry_field_records->at_put(i, entry_fields->at(i));
1223 }
1224 }
1225
1226 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1227 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1228 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1229 if (recorded_klasses != nullptr) {
1230 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1231 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1232 // that are not aot-inited.
1233 int num_to_copy = 0;
1234 for (int i = 0; i < recorded_klasses->length(); i++) {
1235 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1236 if (!subgraph_k->has_aot_initialized_mirror()) {
1237 num_to_copy ++;
1238 }
1239 }
1240
1241 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1242 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1243 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1244 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1245 if (subgraph_k->has_aot_initialized_mirror()) {
1246 continue;
1247 }
1248 if (log_is_enabled(Info, aot, heap)) {
1249 ResourceMark rm;
1250 const char* owner_name = is_special ? "<special>" : _k->external_name();
1251 if (subgraph_k->is_instance_klass()) {
1252 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1253 }
1254 log_info(aot, heap)(
1255 "Archived object klass %s (%2d) => %s",
1256 owner_name, n, subgraph_k->external_name());
1257 }
1258 _subgraph_object_klasses->at_put(n, subgraph_k);
1259 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1260 n++;
1261 }
1262 }
1263
1264 ArchivePtrMarker::mark_pointer(&_k);
1265 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1266 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1267 }
1268
1269 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1270 CompactHashtableWriter* _writer;
1271 public:
1272 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1273
1274 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1275 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1276 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1277 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1278 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1279 _writer->add(hash, AOTCompressedPointers::encode_not_null(record));
1280 }
1281 return true; // keep on iterating
1282 }
1283 };
1284
1285 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1286 ArchivedKlassSubGraphInfoRecord* record =
1287 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1288 record->init(info);
1289 if (info == _dump_time_special_subgraph) {
1290 _run_time_special_subgraph = record;
1291 }
1292 return record;
1293 }
1294
1295 // Build the records of archived subgraph infos, which include:
1296 // - Entry points to all subgraphs from the containing class mirror. The entry
1297 // points are static fields in the mirror. For each entry point, the field
1298 // offset, and value are recorded in the sub-graph
1299 // info. The value is stored back to the corresponding field at runtime.
1300 // - A list of klasses that need to be loaded/initialized before archived
1301 // java object sub-graph can be accessed at runtime.
1302 void HeapShared::write_subgraph_info_table() {
1303 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1304 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1305 CompactHashtableStats stats;
1306
1307 _run_time_subgraph_info_table.reset();
1308
1309 CompactHashtableWriter writer(d_table->number_of_entries(), &stats);
1310 CopyKlassSubGraphInfoToArchive copy(&writer);
1311 d_table->iterate(©);
1312 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1313
1314 #ifndef PRODUCT
1315 if (ArchiveHeapTestClass != nullptr) {
1316 size_t len = strlen(ArchiveHeapTestClass) + 1;
1317 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1318 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1319 _archived_ArchiveHeapTestClass = array;
1320 }
1321 #endif
1322 if (log_is_enabled(Info, aot, heap)) {
1323 print_stats();
1324 }
1325 }
1326
1327 void HeapShared::serialize_tables(SerializeClosure* soc) {
1328
1329 #ifndef PRODUCT
1330 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1331 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1332 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1333 setup_test_class(_test_class_name);
1334 }
1335 #endif
1336
1337 _run_time_subgraph_info_table.serialize_header(soc);
1338 soc->do_ptr(&_run_time_special_subgraph);
1339 }
1340
1341 static void verify_the_heap(Klass* k, const char* which) {
1342 if (VerifyArchivedFields > 0) {
1343 ResourceMark rm;
1344 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1345 which, k->external_name());
1346
1347 if (VerifyArchivedFields == 1) {
1348 VM_Verify verify_op;
1349 VMThread::execute(&verify_op);
1350 } else if (VerifyArchivedFields == 2 && is_init_completed()) {
1351 // At this time, the oop->klass() of some archived objects in the heap may not
1352 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1353 // have enough information (object size, oop maps, etc) so that a GC can be safely
1354 // performed.
1355 //
1356 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1357 // to check for GC safety.
1358 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1359 which, k->external_name());
1360 FlagSetting fs1(VerifyBeforeGC, true);
1361 FlagSetting fs2(VerifyDuringGC, true);
1362 FlagSetting fs3(VerifyAfterGC, true);
1363 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1364 }
1365 }
1366 }
1367
1368 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1369 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1370 //
1371 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1372 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1373 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1374 void HeapShared::resolve_classes(JavaThread* current) {
1375 assert(CDSConfig::is_using_archive(), "runtime only!");
1376 if (CDSConfig::is_using_klass_subgraphs()) {
1377 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1378 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1379 }
1380 }
1381
1382 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1383 for (int i = 0; fields[i].valid(); i++) {
1384 ArchivableStaticFieldInfo* info = &fields[i];
1385 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1386 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1387 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1388 resolve_classes_for_subgraph_of(current, k);
1389 }
1390 }
1391
1392 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1393 JavaThread* THREAD = current;
1394 ExceptionMark em(THREAD);
1395 const ArchivedKlassSubGraphInfoRecord* record =
1396 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1397 if (HAS_PENDING_EXCEPTION) {
1398 CLEAR_PENDING_EXCEPTION;
1399 }
1400 if (record == nullptr) {
1401 clear_archived_roots_of(k);
1402 }
1403 }
1404
1405 static const char* java_lang_invoke_core_klasses[] = {
1406 "java/lang/invoke/Invokers$Holder",
1407 "java/lang/invoke/MethodHandle",
1408 "java/lang/invoke/MethodHandleNatives",
1409 "java/lang/invoke/DirectMethodHandle$Holder",
1410 "java/lang/invoke/DelegatingMethodHandle$Holder",
1411 "java/lang/invoke/LambdaForm$Holder",
1412 "java/lang/invoke/BoundMethodHandle$Species_L",
1413 };
1414
1415 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1416 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1417 int len = sizeof(java_lang_invoke_core_klasses)/sizeof(char*);
1418 for (int i = 0; i < len; i++) {
1419 resolve_or_init(java_lang_invoke_core_klasses[i], true, CHECK);
1420 }
1421 }
1422 }
1423
1424 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1425 // - interned strings
1426 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1427 // - ConstantPool::resolved_references()
1428 // - Universe::<xxx>_exception_instance()
1429 //
1430 // For example, if this enum class is initialized at AOT cache assembly time:
1431 //
1432 // enum Fruit {
1433 // APPLE, ORANGE, BANANA;
1434 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1435 // }
1436 //
1437 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1438 // should be initialized before any Java code can access the Fruit class. Note that
1439 // HashSet itself doesn't necessary need to be an aot-initialized class.
1440 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1441 if (!is_archived_heap_in_use()) {
1442 return;
1443 }
1444
1445 assert( _run_time_special_subgraph != nullptr, "must be");
1446 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1447 if (klasses != nullptr) {
1448 for (int pass = 0; pass < 2; pass ++) {
1449 for (int i = 0; i < klasses->length(); i++) {
1450 Klass* k = klasses->at(i);
1451 if (k->class_loader_data() == nullptr) {
1452 // This class is not yet loaded. We will initialize it in a later phase.
1453 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1454 // but k is part of AOTLinkedClassCategory::BOOT2.
1455 continue;
1456 }
1457 if (k->class_loader() == class_loader()) {
1458 if (pass == 0) {
1459 if (k->is_instance_klass()) {
1460 InstanceKlass::cast(k)->link_class(CHECK);
1461 }
1462 } else {
1463 resolve_or_init(k, /*do_init*/true, CHECK);
1464 }
1465 }
1466 }
1467 }
1468 }
1469 }
1470
1471 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1472 JavaThread* THREAD = current;
1473 if (!CDSConfig::is_using_klass_subgraphs()) {
1474 return; // nothing to do
1475 }
1476
1477 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1478 !CDSConfig::is_using_optimized_module_handling() &&
1479 // archive was created with --module-path
1480 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1481 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1482 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1483 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1484 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1485 AOTClassLocationConfig::runtime()->num_module_paths());
1486 return;
1487 }
1488
1489 ExceptionMark em(THREAD);
1490 const ArchivedKlassSubGraphInfoRecord* record =
1491 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1492
1493 if (HAS_PENDING_EXCEPTION) {
1494 CLEAR_PENDING_EXCEPTION;
1495 // None of the field value will be set if there was an exception when initializing the classes.
1496 // The java code will not see any of the archived objects in the
1497 // subgraphs referenced from k in this case.
1498 return;
1499 }
1500
1501 if (record != nullptr) {
1502 init_archived_fields_for(k, record);
1503 }
1504 }
1505
1506 const ArchivedKlassSubGraphInfoRecord*
1507 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1508 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1509
1510 if (!k->in_aot_cache()) {
1511 return nullptr;
1512 }
1513 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1514 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1515
1516 #ifndef PRODUCT
1517 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1518 _test_class = k;
1519 _test_class_record = record;
1520 }
1521 #endif
1522
1523 // Initialize from archived data. Currently this is done only
1524 // during VM initialization time. No lock is needed.
1525 if (record == nullptr) {
1526 if (log_is_enabled(Info, aot, heap)) {
1527 ResourceMark rm(THREAD);
1528 log_info(aot, heap)("subgraph %s is not recorded",
1529 k->external_name());
1530 }
1531 return nullptr;
1532 } else {
1533 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1534 if (log_is_enabled(Info, aot, heap)) {
1535 ResourceMark rm(THREAD);
1536 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1537 k->external_name());
1538 }
1539 return nullptr;
1540 }
1541
1542 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1543 if (log_is_enabled(Info, aot, heap)) {
1544 ResourceMark rm(THREAD);
1545 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1546 k->external_name());
1547 }
1548 return nullptr;
1549 }
1550
1551 if (log_is_enabled(Info, aot, heap)) {
1552 ResourceMark rm;
1553 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1554 }
1555
1556 resolve_or_init(k, do_init, CHECK_NULL);
1557
1558 // Load/link/initialize the klasses of the objects in the subgraph.
1559 // nullptr class loader is used.
1560 Array<Klass*>* klasses = record->subgraph_object_klasses();
1561 if (klasses != nullptr) {
1562 for (int i = 0; i < klasses->length(); i++) {
1563 Klass* klass = klasses->at(i);
1564 if (!klass->in_aot_cache()) {
1565 return nullptr;
1566 }
1567 resolve_or_init(klass, do_init, CHECK_NULL);
1568 }
1569 }
1570 }
1571
1572 return record;
1573 }
1574
1575 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1576 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1577 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1578 if (k == nullptr) {
1579 return;
1580 }
1581 assert(k->defined_by_boot_loader(), "sanity");
1582 resolve_or_init(k, false, CHECK);
1583 if (do_init) {
1584 resolve_or_init(k, true, CHECK);
1585 }
1586 }
1587
1588 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1589 if (!do_init) {
1590 if (k->class_loader_data() == nullptr) {
1591 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1592 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1593 }
1594 } else {
1595 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1596 if (k->is_instance_klass()) {
1597 InstanceKlass* ik = InstanceKlass::cast(k);
1598 ik->initialize(CHECK);
1599 } else if (k->is_objArray_klass()) {
1600 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1601 oak->initialize(CHECK);
1602 }
1603 }
1604 }
1605
1606 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1607 verify_the_heap(k, "before");
1608
1609 Array<int>* entry_field_records = record->entry_field_records();
1610 if (entry_field_records != nullptr) {
1611 int efr_len = entry_field_records->length();
1612 assert(efr_len % 2 == 0, "sanity");
1613 for (int i = 0; i < efr_len; i += 2) {
1614 int field_offset = entry_field_records->at(i);
1615 int root_index = entry_field_records->at(i+1);
1616 // Load the subgraph entry fields from the record and store them back to
1617 // the corresponding fields within the mirror.
1618 oop v;
1619 if (root_index < 0) {
1620 v = nullptr;
1621 } else {
1622 v = get_root(root_index, /*clear=*/true);
1623 }
1624 oop m = k->java_mirror();
1625 if (k->has_aot_initialized_mirror()) {
1626 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1627 } else {
1628 m->obj_field_put(field_offset, v);
1629 }
1630 log_debug(aot, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1631 }
1632
1633 // Done. Java code can see the archived sub-graphs referenced from k's
1634 // mirror after this point.
1635 if (log_is_enabled(Info, aot, heap)) {
1636 ResourceMark rm;
1637 log_info(aot, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1638 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1639 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1640 }
1641 }
1642
1643 verify_the_heap(k, "after ");
1644 }
1645
1646 void HeapShared::clear_archived_roots_of(Klass* k) {
1647 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1648 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1649 if (record != nullptr) {
1650 Array<int>* entry_field_records = record->entry_field_records();
1651 if (entry_field_records != nullptr) {
1652 int efr_len = entry_field_records->length();
1653 assert(efr_len % 2 == 0, "sanity");
1654 for (int i = 0; i < efr_len; i += 2) {
1655 int root_index = entry_field_records->at(i+1);
1656 clear_root(root_index);
1657 }
1658 }
1659 }
1660 }
1661
1662 // Push all oop fields (or oop array elemenets in case of an objArray) in
1663 // _referencing_obj onto the _stack.
1664 class HeapShared::OopFieldPusher: public BasicOopIterateClosure {
1665 PendingOopStack* _stack;
1666 GrowableArray<oop> _found_oop_fields;
1667 int _level;
1668 bool _record_klasses_only;
1669 KlassSubGraphInfo* _subgraph_info;
1670 oop _referencing_obj;
1671 bool _is_java_lang_ref;
1672 public:
1673 OopFieldPusher(PendingOopStack* stack,
1674 int level,
1675 bool record_klasses_only,
1676 KlassSubGraphInfo* subgraph_info,
1677 oop orig) :
1678 _stack(stack),
1679 _found_oop_fields(),
1680 _level(level),
1681 _record_klasses_only(record_klasses_only),
1682 _subgraph_info(subgraph_info),
1683 _referencing_obj(orig) {
1684 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(orig);
1685 }
1686 void do_oop(narrowOop *p) { OopFieldPusher::do_oop_work(p); }
1687 void do_oop( oop *p) { OopFieldPusher::do_oop_work(p); }
1688
1689 ~OopFieldPusher() {
1690 while (_found_oop_fields.length() > 0) {
1691 // This produces the exact same traversal order as the previous version
1692 // of OopFieldPusher that recurses on the C stack -- a depth-first search,
1693 // walking the oop fields in _referencing_obj by ascending field offsets.
1694 oop obj = _found_oop_fields.pop();
1695 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1696 }
1697 }
1698
1699 protected:
1700 template <class T> void do_oop_work(T *p) {
1701 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_referencing_obj));
1702 oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_referencing_obj, field_offset);
1703 if (obj != nullptr) {
1704 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
1705 // Do not follow these fields. They will be cleared to null.
1706 return;
1707 }
1708
1709 if (!_record_klasses_only && log_is_enabled(Debug, aot, heap)) {
1710 ResourceMark rm;
1711 log_debug(aot, heap)("(%d) %s[%d] ==> " PTR_FORMAT " size %zu %s", _level,
1712 _referencing_obj->klass()->external_name(), field_offset,
1713 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1714 if (log_is_enabled(Trace, aot, heap)) {
1715 LogTarget(Trace, aot, heap) log;
1716 LogStream out(log);
1717 obj->print_on(&out);
1718 }
1719 }
1720
1721 _found_oop_fields.push(obj);
1722 }
1723 }
1724
1725 public:
1726 oop referencing_obj() { return _referencing_obj; }
1727 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1728 };
1729
1730 // Checks if an oop has any non-null oop fields
1731 class PointsToOopsChecker : public BasicOopIterateClosure {
1732 bool _result;
1733
1734 template <class T> void check(T *p) {
1735 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1736 }
1737
1738 public:
1739 PointsToOopsChecker() : _result(false) {}
1740 void do_oop(narrowOop *p) { check(p); }
1741 void do_oop( oop *p) { check(p); }
1742 bool result() { return _result; }
1743 };
1744
1745 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1746 PointsToOopsChecker points_to_oops_checker;
1747 obj->oop_iterate(&points_to_oops_checker);
1748 return CachedOopInfo(OopHandle(Universe::vm_global(), referrer), points_to_oops_checker.result());
1749 }
1750
1751 void HeapShared::init_box_classes(TRAPS) {
1752 if (is_archived_heap_in_use()) {
1753 vmClasses::Boolean_klass()->initialize(CHECK);
1754 vmClasses::Character_klass()->initialize(CHECK);
1755 vmClasses::Float_klass()->initialize(CHECK);
1756 vmClasses::Double_klass()->initialize(CHECK);
1757 vmClasses::Byte_klass()->initialize(CHECK);
1758 vmClasses::Short_klass()->initialize(CHECK);
1759 vmClasses::Integer_klass()->initialize(CHECK);
1760 vmClasses::Long_klass()->initialize(CHECK);
1761 vmClasses::Void_klass()->initialize(CHECK);
1762 }
1763 }
1764
1765 // (1) If orig_obj has not been archived yet, archive it.
1766 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1767 // trace all objects that are reachable from it, and make sure these objects are archived.
1768 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1769 // were already archived when this function is called)
1770 bool HeapShared::archive_reachable_objects_from(int level,
1771 KlassSubGraphInfo* subgraph_info,
1772 oop orig_obj) {
1773 assert(orig_obj != nullptr, "must be");
1774 PendingOopStack stack;
1775 stack.push(PendingOop(orig_obj, nullptr, level));
1776
1777 while (stack.length() > 0) {
1778 PendingOop po = stack.pop();
1779 _object_being_archived = po;
1780 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1781 _object_being_archived = PendingOop();
1782
1783 if (!status) {
1784 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1785 // as the Java code will take care of initializing this field dynamically.
1786 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1787 return false;
1788 }
1789 }
1790
1791 return true;
1792 }
1793
1794 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1795 oop orig_obj, oop referrer) {
1796 assert(orig_obj != nullptr, "must be");
1797 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1798 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1799 // If you get an error here, you probably made a change in the JDK library that has added
1800 // these objects that are referenced (directly or indirectly) by static fields.
1801 ResourceMark rm;
1802 log_error(aot, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1803 debug_trace();
1804 AOTMetaspace::unrecoverable_writing_error();
1805 }
1806
1807 if (log_is_enabled(Debug, aot, heap) && java_lang_Class::is_instance(orig_obj)) {
1808 ResourceMark rm;
1809 LogTarget(Debug, aot, heap) log;
1810 LogStream out(log);
1811 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1812 Klass* k = java_lang_Class::as_Klass(orig_obj);
1813 if (k != nullptr) {
1814 out.print("%s", k->external_name());
1815 } else {
1816 out.print("primitive");
1817 }
1818 out.print_cr("; scratch mirror = " PTR_FORMAT,
1819 p2i(scratch_java_mirror(orig_obj)));
1820 }
1821
1822 if (java_lang_Class::is_instance(orig_obj)) {
1823 Klass* k = java_lang_Class::as_Klass(orig_obj);
1824 if (RegeneratedClasses::has_been_regenerated(k)) {
1825 orig_obj = RegeneratedClasses::get_regenerated_object(k)->java_mirror();
1826 }
1827 }
1828
1829 if (CDSConfig::is_dumping_aot_linked_classes()) {
1830 if (java_lang_Class::is_instance(orig_obj)) {
1831 orig_obj = scratch_java_mirror(orig_obj);
1832 assert(orig_obj != nullptr, "must be archived");
1833 }
1834 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1835 // Without CDSConfig::is_dumping_aot_linked_classes(), we only allow archived objects to
1836 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1837 // very early by HeapShared::init_box_classes().
1838 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1839 || java_lang_Class::is_primitive(orig_obj)
1840 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1841 || orig_obj == vmClasses::Character_klass()->java_mirror()
1842 || orig_obj == vmClasses::Float_klass()->java_mirror()
1843 || orig_obj == vmClasses::Double_klass()->java_mirror()
1844 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1845 || orig_obj == vmClasses::Short_klass()->java_mirror()
1846 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1847 || orig_obj == vmClasses::Long_klass()->java_mirror()
1848 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1849 orig_obj = scratch_java_mirror(orig_obj);
1850 assert(orig_obj != nullptr, "must be archived");
1851 } else {
1852 // If you get an error here, you probably made a change in the JDK library that has added a Class
1853 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1854 // defined at the top of this file.
1855 log_error(aot, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1856 debug_trace();
1857 AOTMetaspace::unrecoverable_writing_error();
1858 }
1859 }
1860
1861 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1862 // orig_obj has already been archived and traced. Nothing more to do.
1863 return true;
1864 } else {
1865 set_has_been_seen_during_subgraph_recording(orig_obj);
1866 }
1867
1868 bool already_archived = has_been_archived(orig_obj);
1869 bool record_klasses_only = already_archived;
1870 if (!already_archived) {
1871 ++_num_new_archived_objs;
1872 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1873 // Skip archiving the sub-graph referenced from the current entry field.
1874 ResourceMark rm;
1875 log_error(aot, heap)(
1876 "Cannot archive the sub-graph referenced from %s object ("
1877 PTR_FORMAT ") size %zu, skipped.",
1878 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1879 if (level == 1) {
1880 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1881 // as the Java code will take care of initializing this field dynamically.
1882 return false;
1883 } else {
1884 // We don't know how to handle an object that has been archived, but some of its reachable
1885 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1886 // we have a real use case.
1887 AOTMetaspace::unrecoverable_writing_error();
1888 }
1889 }
1890 }
1891
1892 Klass *orig_k = orig_obj->klass();
1893 subgraph_info->add_subgraph_object_klass(orig_k);
1894
1895 {
1896 // Find all the oops that are referenced by orig_obj, push them onto the stack
1897 // so we can work on them next.
1898 ResourceMark rm;
1899 OopFieldPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1900 orig_obj->oop_iterate(&pusher);
1901 }
1902
1903 if (CDSConfig::is_dumping_aot_linked_classes()) {
1904 // The enum klasses are archived with aot-initialized mirror.
1905 // See AOTClassInitializer::can_archive_initialized_mirror().
1906 } else {
1907 // This is legacy support for enum classes before JEP 483 -- we cannot rerun
1908 // the enum's <clinit> in the production run, so special handling is needed.
1909 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1910 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1911 }
1912 }
1913
1914 return true;
1915 }
1916
1917 //
1918 // Start from the given static field in a java mirror and archive the
1919 // complete sub-graph of java heap objects that are reached directly
1920 // or indirectly from the starting object by following references.
1921 // Sub-graph archiving restrictions (current):
1922 //
1923 // - All classes of objects in the archived sub-graph (including the
1924 // entry class) must be boot class only.
1925 // - No java.lang.Class instance (java mirror) can be included inside
1926 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1927 //
1928 // The Java heap object sub-graph archiving process (see OopFieldPusher):
1929 //
1930 // 1) Java object sub-graph archiving starts from a given static field
1931 // within a Class instance (java mirror). If the static field is a
1932 // reference field and points to a non-null java object, proceed to
1933 // the next step.
1934 //
1935 // 2) Archives the referenced java object. If an archived copy of the
1936 // current object already exists, updates the pointer in the archived
1937 // copy of the referencing object to point to the current archived object.
1938 // Otherwise, proceed to the next step.
1939 //
1940 // 3) Follows all references within the current java object and recursively
1941 // archive the sub-graph of objects starting from each reference.
1942 //
1943 // 4) Updates the pointer in the archived copy of referencing object to
1944 // point to the current archived object.
1945 //
1946 // 5) The Klass of the current java object is added to the list of Klasses
1947 // for loading and initializing before any object in the archived graph can
1948 // be accessed at runtime.
1949 //
1950 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1951 const char* klass_name,
1952 int field_offset,
1953 const char* field_name) {
1954 precond(CDSConfig::is_dumping_klass_subgraphs());
1955 assert(k->defined_by_boot_loader(), "must be boot class");
1956
1957 oop m = k->java_mirror();
1958
1959 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1960 oop f = m->obj_field(field_offset);
1961
1962 log_debug(aot, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1963
1964 if (!CompressedOops::is_null(f)) {
1965 if (log_is_enabled(Trace, aot, heap)) {
1966 LogTarget(Trace, aot, heap) log;
1967 LogStream out(log);
1968 f->print_on(&out);
1969 }
1970
1971 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1972 if (!success) {
1973 log_error(aot, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1974 klass_name, field_name);
1975 } else {
1976 // Note: the field value is not preserved in the archived mirror.
1977 // Record the field as a new subGraph entry point. The recorded
1978 // information is restored from the archive at runtime.
1979 subgraph_info->add_subgraph_entry_field(field_offset, f);
1980 log_info(aot, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1981 }
1982 } else {
1983 // The field contains null, we still need to record the entry point,
1984 // so it can be restored at runtime.
1985 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1986 }
1987 }
1988
1989 #ifndef PRODUCT
1990 class VerifySharedOopClosure: public BasicOopIterateClosure {
1991 public:
1992 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1993 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1994
1995 protected:
1996 template <class T> void do_oop_work(T *p) {
1997 oop obj = HeapAccess<>::oop_load(p);
1998 if (obj != nullptr) {
1999 HeapShared::verify_reachable_objects_from(obj);
2000 }
2001 }
2002 };
2003
2004 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
2005 precond(CDSConfig::is_dumping_klass_subgraphs());
2006 assert(k->defined_by_boot_loader(), "must be boot class");
2007
2008 oop m = k->java_mirror();
2009 oop f = m->obj_field(field_offset);
2010 if (!CompressedOops::is_null(f)) {
2011 verify_subgraph_from(f);
2012 }
2013 }
2014
2015 void HeapShared::verify_subgraph_from(oop orig_obj) {
2016 if (!has_been_archived(orig_obj)) {
2017 // It's OK for the root of a subgraph to be not archived. See comments in
2018 // archive_reachable_objects_from().
2019 return;
2020 }
2021
2022 // Verify that all objects reachable from orig_obj are archived.
2023 init_seen_objects_table();
2024 verify_reachable_objects_from(orig_obj);
2025 delete_seen_objects_table();
2026 }
2027
2028 void HeapShared::verify_reachable_objects_from(oop obj) {
2029 _num_total_verifications ++;
2030 if (java_lang_Class::is_instance(obj)) {
2031 Klass* k = java_lang_Class::as_Klass(obj);
2032 if (RegeneratedClasses::has_been_regenerated(k)) {
2033 k = RegeneratedClasses::get_regenerated_object(k);
2034 obj = k->java_mirror();
2035 }
2036 obj = scratch_java_mirror(obj);
2037 assert(obj != nullptr, "must be");
2038 }
2039 if (!has_been_seen_during_subgraph_recording(obj)) {
2040 set_has_been_seen_during_subgraph_recording(obj);
2041 assert(has_been_archived(obj), "must be");
2042 VerifySharedOopClosure walker;
2043 obj->oop_iterate(&walker);
2044 }
2045 }
2046 #endif
2047
2048 void HeapShared::check_special_subgraph_classes() {
2049 if (CDSConfig::is_dumping_aot_linked_classes()) {
2050 // We can have aot-initialized classes (such as Enums) that can reference objects
2051 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
2052 // aot-initialize classes that are "safe".
2053 //
2054 // TODO: we need an automatic tool that checks the safety of aot-initialized
2055 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
2056 return;
2057 } else {
2058 // In this case, the special subgraph should contain a few specific types
2059 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
2060 int num = klasses->length();
2061 for (int i = 0; i < num; i++) {
2062 Klass* subgraph_k = klasses->at(i);
2063 Symbol* name = subgraph_k->name();
2064 if (subgraph_k->is_instance_klass() &&
2065 name != vmSymbols::java_lang_Class() &&
2066 name != vmSymbols::java_lang_String() &&
2067 name != vmSymbols::java_lang_ArithmeticException() &&
2068 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
2069 name != vmSymbols::java_lang_ArrayStoreException() &&
2070 name != vmSymbols::java_lang_ClassCastException() &&
2071 name != vmSymbols::java_lang_InternalError() &&
2072 name != vmSymbols::java_lang_NullPointerException() &&
2073 name != vmSymbols::jdk_internal_vm_PreemptedException()) {
2074 ResourceMark rm;
2075 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
2076 }
2077 }
2078 }
2079 }
2080
2081 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
2082 HeapShared::PendingOop HeapShared::_object_being_archived;
2083 size_t HeapShared::_num_new_walked_objs;
2084 size_t HeapShared::_num_new_archived_objs;
2085 size_t HeapShared::_num_old_recorded_klasses;
2086
2087 size_t HeapShared::_num_total_subgraph_recordings = 0;
2088 size_t HeapShared::_num_total_walked_objs = 0;
2089 size_t HeapShared::_num_total_archived_objs = 0;
2090 size_t HeapShared::_num_total_recorded_klasses = 0;
2091 size_t HeapShared::_num_total_verifications = 0;
2092
2093 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2094 return _seen_objects_table->get(obj) != nullptr;
2095 }
2096
2097 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2098 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2099 _seen_objects_table->put_when_absent(obj, true);
2100 _seen_objects_table->maybe_grow();
2101 ++ _num_new_walked_objs;
2102 }
2103
2104 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2105 log_info(aot, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2106 init_subgraph_info(k, is_full_module_graph);
2107 init_seen_objects_table();
2108 _num_new_walked_objs = 0;
2109 _num_new_archived_objs = 0;
2110 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2111 }
2112
2113 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2114 size_t num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2115 _num_old_recorded_klasses;
2116 log_info(aot, heap)("Done recording subgraph(s) for archived fields in %s: "
2117 "walked %zu objs, archived %zu new objs, recorded %zu classes",
2118 class_name, _num_new_walked_objs, _num_new_archived_objs,
2119 num_new_recorded_klasses);
2120
2121 delete_seen_objects_table();
2122
2123 _num_total_subgraph_recordings ++;
2124 _num_total_walked_objs += _num_new_walked_objs;
2125 _num_total_archived_objs += _num_new_archived_objs;
2126 _num_total_recorded_klasses += num_new_recorded_klasses;
2127 }
2128
2129 class ArchivableStaticFieldFinder: public FieldClosure {
2130 InstanceKlass* _ik;
2131 Symbol* _field_name;
2132 bool _found;
2133 int _offset;
2134 public:
2135 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2136 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2137
2138 virtual void do_field(fieldDescriptor* fd) {
2139 if (fd->name() == _field_name) {
2140 assert(!_found, "fields can never be overloaded");
2141 if (is_reference_type(fd->field_type())) {
2142 _found = true;
2143 _offset = fd->offset();
2144 }
2145 }
2146 }
2147 bool found() { return _found; }
2148 int offset() { return _offset; }
2149 };
2150
2151 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2152 TRAPS) {
2153 for (int i = 0; fields[i].valid(); i++) {
2154 ArchivableStaticFieldInfo* info = &fields[i];
2155 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2156 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2157 ResourceMark rm; // for stringStream::as_string() etc.
2158
2159 #ifndef PRODUCT
2160 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2161 const char* test_class_name = ArchiveHeapTestClass;
2162 #else
2163 bool is_test_class = false;
2164 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2165 #endif
2166
2167 if (is_test_class) {
2168 log_warning(aot)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2169 }
2170
2171 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2172 if (HAS_PENDING_EXCEPTION) {
2173 CLEAR_PENDING_EXCEPTION;
2174 stringStream st;
2175 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2176 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2177 }
2178
2179 if (!k->is_instance_klass()) {
2180 stringStream st;
2181 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2182 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2183 }
2184
2185 InstanceKlass* ik = InstanceKlass::cast(k);
2186 assert(InstanceKlass::cast(ik)->defined_by_boot_loader(),
2187 "Only support boot classes");
2188
2189 if (is_test_class) {
2190 if (ik->module()->is_named()) {
2191 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2192 // core-lib classes. You need to at least append to the bootclasspath.
2193 stringStream st;
2194 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2195 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2196 }
2197
2198 if (ik->package() != nullptr) {
2199 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2200 stringStream st;
2201 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2202 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2203 }
2204 } else {
2205 if (ik->module()->name() != vmSymbols::java_base()) {
2206 // We don't want to deal with cases when a module is unavailable at runtime.
2207 // FUTURE -- load from archived heap only when module graph has not changed
2208 // between dump and runtime.
2209 stringStream st;
2210 st.print("%s is not in java.base module", info->klass_name);
2211 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2212 }
2213 }
2214
2215 if (is_test_class) {
2216 log_warning(aot)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2217 }
2218 ik->initialize(CHECK);
2219
2220 ArchivableStaticFieldFinder finder(ik, field_name);
2221 ik->do_local_static_fields(&finder);
2222 if (!finder.found()) {
2223 stringStream st;
2224 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2225 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2226 }
2227
2228 info->klass = ik;
2229 info->offset = finder.offset();
2230 }
2231 }
2232
2233 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2234 assert(CDSConfig::is_dumping_heap(), "must be");
2235 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2236 if (CDSConfig::is_dumping_klass_subgraphs()) {
2237 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2238 if (CDSConfig::is_dumping_full_module_graph()) {
2239 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2240 }
2241 }
2242 }
2243
2244 #ifndef PRODUCT
2245 void HeapShared::setup_test_class(const char* test_class_name) {
2246 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2247 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2248 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2249 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2250
2251 if (test_class_name != nullptr) {
2252 p[num_slots - 2].klass_name = test_class_name;
2253 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2254 }
2255 }
2256
2257 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2258 // during runtime. This may be called before the module system is initialized so
2259 // we cannot rely on InstanceKlass::module(), etc.
2260 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2261 if (_test_class != nullptr) {
2262 if (ik == _test_class) {
2263 return true;
2264 }
2265 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2266 if (klasses == nullptr) {
2267 return false;
2268 }
2269
2270 for (int i = 0; i < klasses->length(); i++) {
2271 Klass* k = klasses->at(i);
2272 if (k == ik) {
2273 Symbol* name;
2274 if (k->is_instance_klass()) {
2275 name = InstanceKlass::cast(k)->name();
2276 } else if (k->is_objArray_klass()) {
2277 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2278 if (!bk->is_instance_klass()) {
2279 return false;
2280 }
2281 name = bk->name();
2282 } else {
2283 return false;
2284 }
2285
2286 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2287 // to be:
2288 // (A) java.base classes (which must not be in the unnamed module)
2289 // (B) test classes which must be in the unnamed package of the unnamed module.
2290 // So if we see a '/' character in the class name, it must be in (A);
2291 // otherwise it must be in (B).
2292 if (name->index_of_at(0, "/", 1) >= 0) {
2293 return false; // (A)
2294 }
2295
2296 return true; // (B)
2297 }
2298 }
2299 }
2300
2301 return false;
2302 }
2303
2304 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2305 Klass* k = _test_class;
2306 if (k != nullptr && is_archived_heap_in_use()) {
2307 JavaThread* THREAD = current;
2308 ExceptionMark em(THREAD);
2309 const ArchivedKlassSubGraphInfoRecord* record =
2310 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2311
2312 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2313 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2314 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2315 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2316 if (record != nullptr) {
2317 init_archived_fields_for(k, record);
2318 }
2319 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2320 }
2321 }
2322 #endif
2323
2324 void HeapShared::init_for_dumping(TRAPS) {
2325 if (CDSConfig::is_dumping_heap()) {
2326 setup_test_class(ArchiveHeapTestClass);
2327 init_subgraph_entry_fields(CHECK);
2328 }
2329 }
2330
2331 void HeapShared::init_heap_writer() {
2332 if (HeapShared::is_writing_streaming_mode()) {
2333 AOTStreamedHeapWriter::init();
2334 } else {
2335 AOTMappedHeapWriter::init();
2336 }
2337 }
2338
2339 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2340 bool is_full_module_graph) {
2341 _num_total_subgraph_recordings = 0;
2342 _num_total_walked_objs = 0;
2343 _num_total_archived_objs = 0;
2344 _num_total_recorded_klasses = 0;
2345 _num_total_verifications = 0;
2346
2347 // For each class X that has one or more archived fields:
2348 // [1] Dump the subgraph of each archived field
2349 // [2] Create a list of all the class of the objects that can be reached
2350 // by any of these static fields.
2351 // At runtime, these classes are initialized before X's archived fields
2352 // are restored by HeapShared::initialize_from_archived_subgraph().
2353 for (int i = 0; fields[i].valid(); ) {
2354 ArchivableStaticFieldInfo* info = &fields[i];
2355 const char* klass_name = info->klass_name;
2356 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2357
2358 // If you have specified consecutive fields of the same klass in
2359 // fields[], these will be archived in the same
2360 // {start_recording_subgraph ... done_recording_subgraph} pass to
2361 // save time.
2362 for (; fields[i].valid(); i++) {
2363 ArchivableStaticFieldInfo* f = &fields[i];
2364 if (f->klass_name != klass_name) {
2365 break;
2366 }
2367
2368 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2369 f->offset, f->field_name);
2370 }
2371 done_recording_subgraph(info->klass, klass_name);
2372 }
2373
2374 log_info(aot, heap)("Archived subgraph records = %zu",
2375 _num_total_subgraph_recordings);
2376 log_info(aot, heap)(" Walked %zu objects", _num_total_walked_objs);
2377 log_info(aot, heap)(" Archived %zu objects", _num_total_archived_objs);
2378 log_info(aot, heap)(" Recorded %zu klasses", _num_total_recorded_klasses);
2379
2380 #ifndef PRODUCT
2381 for (int i = 0; fields[i].valid(); i++) {
2382 ArchivableStaticFieldInfo* f = &fields[i];
2383 verify_subgraph_from_static_field(f->klass, f->offset);
2384 }
2385 log_info(aot, heap)(" Verified %zu references", _num_total_verifications);
2386 #endif
2387 }
2388
2389 bool HeapShared::is_interned_string(oop obj) {
2390 if (!java_lang_String::is_instance(obj)) {
2391 return false;
2392 }
2393
2394 ResourceMark rm;
2395 int len = 0;
2396 jchar* name = java_lang_String::as_unicode_string_or_null(obj, len);
2397 if (name == nullptr) {
2398 fatal("Insufficient memory for dumping");
2399 }
2400 return StringTable::lookup(name, len) == obj;
2401 }
2402
2403 bool HeapShared::is_dumped_interned_string(oop o) {
2404 return is_interned_string(o) && has_been_archived(o);
2405 }
2406
2407 // These tables should be used only within the CDS safepoint, so
2408 // delete them before we exit the safepoint. Otherwise the table will
2409 // contain bad oops after a GC.
2410 void HeapShared::delete_tables_with_raw_oops() {
2411 assert(_seen_objects_table == nullptr, "should have been deleted");
2412
2413 if (is_writing_mapping_mode()) {
2414 AOTMappedHeapWriter::delete_tables_with_raw_oops();
2415 } else {
2416 assert(is_writing_streaming_mode(), "what other mode?");
2417 AOTStreamedHeapWriter::delete_tables_with_raw_oops();
2418 }
2419 }
2420
2421 void HeapShared::debug_trace() {
2422 ResourceMark rm;
2423 oop referrer = _object_being_archived.referrer();
2424 if (referrer != nullptr) {
2425 LogStream ls(Log(aot, heap)::error());
2426 ls.print_cr("Reference trace");
2427 CDSHeapVerifier::trace_to_root(&ls, referrer);
2428 }
2429 }
2430
2431 #ifndef PRODUCT
2432 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2433 // region. This way we can quickly relocate all the pointers without using
2434 // BasicOopIterateClosure at runtime.
2435 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2436 void* _start;
2437 BitMap *_oopmap;
2438 size_t _num_total_oops;
2439 size_t _num_null_oops;
2440 public:
2441 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2442 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2443
2444 virtual void do_oop(narrowOop* p) {
2445 assert(UseCompressedOops, "sanity");
2446 _num_total_oops ++;
2447 narrowOop v = *p;
2448 if (!CompressedOops::is_null(v)) {
2449 size_t idx = p - (narrowOop*)_start;
2450 _oopmap->set_bit(idx);
2451 } else {
2452 _num_null_oops ++;
2453 }
2454 }
2455 virtual void do_oop(oop* p) {
2456 assert(!UseCompressedOops, "sanity");
2457 _num_total_oops ++;
2458 if ((*p) != nullptr) {
2459 size_t idx = p - (oop*)_start;
2460 _oopmap->set_bit(idx);
2461 } else {
2462 _num_null_oops ++;
2463 }
2464 }
2465 size_t num_total_oops() const { return _num_total_oops; }
2466 size_t num_null_oops() const { return _num_null_oops; }
2467 };
2468 #endif
2469
2470 void HeapShared::count_allocation(size_t size) {
2471 _total_obj_count ++;
2472 _total_obj_size += size;
2473 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2474 if (size <= (size_t(1) << i)) {
2475 _alloc_count[i] ++;
2476 _alloc_size[i] += size;
2477 return;
2478 }
2479 }
2480 }
2481
2482 static double avg_size(size_t size, size_t count) {
2483 double avg = 0;
2484 if (count > 0) {
2485 avg = double(size * HeapWordSize) / double(count);
2486 }
2487 return avg;
2488 }
2489
2490 void HeapShared::print_stats() {
2491 size_t huge_count = _total_obj_count;
2492 size_t huge_size = _total_obj_size;
2493
2494 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2495 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2496 size_t count = _alloc_count[i];
2497 size_t size = _alloc_size[i];
2498 log_info(aot, heap)("%8zu objects are <= %-6zu"
2499 " bytes (total %8zu bytes, avg %8.1f bytes)",
2500 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2501 huge_count -= count;
2502 huge_size -= size;
2503 }
2504
2505 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2506 ", avg %8.1f bytes)",
2507 huge_count, huge_size * HeapWordSize,
2508 avg_size(huge_size, huge_count));
2509 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2510 ", avg %8.1f bytes)",
2511 _total_obj_count, _total_obj_size * HeapWordSize,
2512 avg_size(_total_obj_size, _total_obj_count));
2513 }
2514
2515 bool HeapShared::is_metadata_field(oop src_obj, int offset) {
2516 bool result = false;
2517 do_metadata_offsets(src_obj, [&](int metadata_offset) {
2518 if (metadata_offset == offset) {
2519 result = true;
2520 }
2521 });
2522 return result;
2523 }
2524
2525 void HeapShared::remap_dumped_metadata(oop src_obj, address archived_object) {
2526 do_metadata_offsets(src_obj, [&](int offset) {
2527 Metadata** buffered_field_addr = (Metadata**)(archived_object + offset);
2528 Metadata* native_ptr = *buffered_field_addr;
2529
2530 if (native_ptr == nullptr) {
2531 return;
2532 }
2533
2534 if (RegeneratedClasses::has_been_regenerated(native_ptr)) {
2535 native_ptr = RegeneratedClasses::get_regenerated_object(native_ptr);
2536 }
2537
2538 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
2539 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
2540 *buffered_field_addr = (Metadata*)requested_native_ptr;
2541 });
2542 }
2543
2544 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2545 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2546 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2547 if (k == nullptr) {
2548 return false;
2549 } else {
2550 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2551 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2552 fieldDescriptor fd;
2553 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2554 oop m = k->java_mirror();
2555 oop f = m->obj_field(fd.offset());
2556 if (CompressedOops::is_null(f)) {
2557 return false;
2558 }
2559 } else {
2560 return false;
2561 }
2562 }
2563 return true;
2564 }
2565
2566 #endif // INCLUDE_CDS_JAVA_HEAP